Mounting structure for pistol barrels



Nov. 19, 1968 F, A. PACHMAYR ET AL 3,411,408

MOUNTING STRUCTURE FOR PISTOL BARRELS 2 Sheets-Sheet 2 Filed Dec. 29, 1966 0 2 ul Q mg um um N E wm mm Fen/we A Pncnmn Fawn/2o B .M/LLER INVENTORS 2/4/4- fl-r oPA/EYS United States Patent 3,411,408 MOUNTING STRUCTURE FOR PISTOL BARRELS Frank A. Pachmayr and Edward B. Miller, Los Angeles, Calif., assignors to Pachmayr Gun Works, Inc., Los Angeles, Calif., a corporation of California Filed Dec. 29, 1966, Ser. No. 605,829 14 Claims. (Cl. 89196) ABSTRACT OF THE DISCLOSURE A gun having a barrel mounted within a slide which recoils relative to the barrel, while the breech end of the barrel swings slightly downwardly during recoil, and with the gun including a bushing disposed about the barrel and confined axially between a threadedly mounted adjustable retaining ring and a forwardly facing shoulder surface in the slide in a relation confining and guiding the bushing for slight pivotal movement relative to the slide in correspondence with the downward swinging movement of the breech end of the barrel.

This invention relates to an improved arrangement for mounting the barrel of a gun of the type having a slide which reciprocates rearwardly relative to the barrel upon firing of the gun. Certain features of the invention, in their broadest sense, have been disclosed in our copending application Ser. No. 605,825 filed of even date herewith on Gun Barrel Locating Structure.

In guns of the type with which the present invention is concerned, the recoiling slide may be mounted to the receiver or main body of the gun for the desired front to rear recoiling movement, while the barrel of the gun is mounted for only very slight movement relative to the receiver upon recoil. More particularly, the barrel is preferably mounted so that its breech end swings slightly rearwardly and downwardly upon each recoiling operation, just far enough to avoid interference by the barrel with the rearward motion of the slide. The breech end of the barrel is supported for this slight swinging movement by means of an appropriate linkage movably connecting that end of the barrel to the receiver or gun body. The forward end of the barrel is located by a bushing contained within and carried by the slide, but in conventional guns of this general type difficulties have been encountered in confining the forward end of the barrel effectively enough by this bushing arrangement to assure accuracy in firing the gun. That is, because of the necessity for retracting movement of the slide, and for downward swinging movement of the breech end of the barrel, the conventional type of bushing structure utilized at the forward end of the barrel has been incapable of preventing slight transverse shifting movement of the barrel at that forward location, which shifting movement has introduced errors into the aiming and firing of the gun.

The general object of the present invention is to provide an improved bushing arrangement for movably locating the forward end of such a barrel relative to a recoilable slide, in a manner very positively locating the barrel under all operating conditions, and preventing even the slightest displacement of the barrel from a predetermined accurately controlled position of alignment with the other parts of the gun, and particularly with the aiming sights. For this purpose, I employ a bushing which is disposed about the barrel, and which is confined axially between two locating surfaces, one of which is formed on means carried by the slide, while the other is formed on a retaining structure detachably connectible to the slide. The retaining structure may take the form of a ring or tubular element which is threadedly connectible into the slide. The locating surfaces which are engaged by the bushing ice or its equivalent are designed to so retain the bushing as to guide the latter for a pivotal, desirably universal type of motion, so that the bushing and the contained barrel may swing as necessary to enable the discussed downward and rearward retracting motion of the barrel upon recoil. For thus guiding the bushing, we may utilize one or more spherical surfaces on the bushing and/ or on the parts by which the bushing is retained, preferably on all of these parts, to locate the bushing for only the desired pivotal or universal movement relative to the slide and the retaining structure. Also, the bushing may be a constrictable bushing, which is preferably tightened radially inwardly against the barrel to a no-clearance condition by adjustment of the retaining structure by which the bushing is held in place.

The retaining ring or structure may be held in any of various different adjusted positions by appropriate holding means. In the preferred arrangement, this result is achieved by the employment of detenting irregularities on the retaining ring and on a plug which is urged forwardly by the recoil spring of the gun, with these irregularities being effective to hold the ring in different positions, but being releasable to enable adjustment of the ring and bushing a desired.

The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiment illustrated in the accompanying drawing, in which:

FIG. 1 is a side View, partially broken away, of an automatic pistol constructed in accordance with the invention;

FIG. 2 shows the pistol of FIG. 1 in its full recoil position;

FIGS. 3 and 4 are sections taken on lines 33 and 44 respectively of FIG. 1;

FIG. 5 is a section on line 55 of FIG. 2; and

FIG. 6 is an enlarged section on line 6-6 of FIG. 5.

The pistol 10 illustrated in FIG. 1 will be recognized as a basically conventional gun, having a receiver or main body 11, to the upper side of which there is mounted a slide 12, which is guided for recoiling movement relative to the receiver between the battery or firing position of FIG. 1 and the recoiled position of FIG. 2. The barrel of the gun is illustrated at 13, and may be considered as essentially tubular, being internally essentially cylindrical, and externally essentially cylindrical except near its breech end 14 where the barrel is somewhat enlarged and shaped as shown.

The receiver 11 has the usual handle portion 15 adapted to contain a magazine 16 by which a series of rounds of ammunition are successively fed upwardly and into the breech end of the barrel, for firing and ultimate ejection through an opening 17 at the upper side of the slide. The gun is of course fired by the usual trigger represented at 18. The recoiling motion of slide 12 is yieldingly resisted by a conventional coiled compression spring 19, which bears rearwardly against a spring guide 20, which in turn acts rearwardly against an appropriate shoulder formed on the receiver. The forward end of spring 19 is received within and exerts force forwardly against a plug 21 contained within and carried by the slide 12.

To guide the slide 12 for its recoiling movement between the FIG. 1 and FIG. 2 positions, the slide has two edges 22 extending along opposite sides of the receiver and forming guide ways 23 (FIG. 5) slidably interfitting with mating guide ways 26 formed on the receiver. The front to rear axis along which slide 12 recoils relative to the receiver is represented at 27 in FIG. 1. The forward portion of the slide is hollow and has an inner cylindrical surface 28 (FIG. 1) centered about axis 27 and of a diam eter larger than the main external diameter of barrel 13, to receive the barrel movably within the slide. Near its forward end, the slide has a partial spherical surface 29 (FIG. 1), disposed about a center 30 which lies on the axis 27 of surface 28. This partial spherical surface extends forwardly from the location designated 30 in FIG. 6 to the location designated 31, beyond which the inner surface of the slide may form first a cylindrical surface 32 and then a series of internal threads 33 centered about axis 27. As will be understood best in FIG. 5, surfaces 29 and 32 are both circularly continuous through considerable more than 180 degrees about an axis 27, and are interrupted only at an axially extending gap or slit 129 which is beneath the barrel and communicates with a later-tobe-discussed passage 49 in a lower front portion 149 of the slide.

Disposed about the barrel l3 and within slide 12, near the forward end of the slide, there is provided a barrel locating bushing 34 for attaining the barrel locating purpose of the present invention. This bushing 34 may be annular, except that the bushing is desirably interrupted at one point about its periphery, as indicated at 35 in FIG. 5. Internally, bushing 34 has an inner cylindrical surface 36 which normally assumes a diameter substantially the same as the outer cylindrical surface 37 of barrel 13. Externally, bushing 34 has an outer spherical surface 38, centered about the point 30, and having the same curvature as the previously mentioned surface 29 within the slide. The bushing 34 is formed of a material, such as a suitable metal, which may be substantially rigid, but which has a capacity for slight resilient deformability, so that the bushing may be forceably constricted radially inwardly to a slightly reduced diameter, in order to assure a closely fitting engagement with the outer surface of the barrel.

Bushing 34 is retained in its illustrated assembled position within the slide by means of a retaining ring 39, which may be substantially annular, and have an inner cylindrical surface 40 of a diameter slightly greater than the diameter of outer surface 37 of the barrel. Externally, ring 39 may have external threads 41 which are threadedly and adjustably engageable with internal threads 33 formed on the slide, to adjust ring 39 rearwardly and forwardly relative to the slide. At its rear end, the ring has an annular surface 42 which has the same spherical curvature as do surfaces 29 and 38 of the slide and bushing, being centered about the point 30 of FIG. 1, to coact with surface 29 in mounting the bushing for universal motion about center 30, and for pivotal movement about an axis extending through center 30 and extending horizontally and transversely of axis 27.

At its forward end, retaining ring 39 has a radially outwardly projecting annular flange 43, which has a series of rearwardly projecting evenly circularly spaced detent teeth 44 engageable with a forwardly projecting tooth or projection 45 formed on a depending tongue portion of plug 21. Teeth 44 and projection 45 may have the tapering configuration illustrated in FIG. 3, typically of degrees cross section.

Plug 21 may be substantially cylindrical about an axis 46 disposed parallel to and beneath axis 27, and may contain a passage 47 within which the forward end of spring 19 is received, with this spring bearing forwardly against a transverse shoulder 48 formed at the front end of the plug. The plug is received within a cylindrical passage 49 formed in the lower front portion 149 of the slide, and has its downwardly projecting tongue portion 50 received within an axially extending notch or slit 51 formed in the slide, to retain the plug against rotary motion about axis 46. The plug may be inserted into passage 49 in the slide from the forward open end of that passage, and is retained in its FIG. 1 position of confinement within passage 49 by engagement of flange 43 of ring 39 with projection 45 of the plug.

At its breech end, the barrel 13 has a lug or pair of lugs 52 (FIG. 1), which project downwardly and are pivotally connected by a pin 53 to a link 54, whose second end is in turn pivotally connected by a pin 55 to receiver 11. Pins 53 and 55 extend parallel to one another, and horizontally, and essentially transversely of the axis 27 of retraction of slide 12. In the battery position of FIG. 1, ribs 56 at the upper side of the barrel are received within semicircular notches or grooves 57 formed in the slide.

To describe a cycle of operation of the gun illustrated in the figures, assume first of all that the gun is in the condition of FIG. 1, with the slide in its forwardmost position, and with barrel .13 aligned with the gun sights 58 and 59 on the slide. The user fires the gun by pulling trigger 13, to cause the hammer to fire a shell within the breech end of the barrel. The resulting gases of combustion within the barrel cause slide 12 to recoil rearwardly along axis 27, and cause the breech end of the barrel to swing rearwardly and downwardly, as permitted by link 54, to the FIG. 2 position. As the breech end of the barrel moves downwardly, its forward end and the surrounding bushing 34 pivot slightly about a horizontal axis extending through point 30 of FIG. 1, while at the same time the bushing slides rearwardly along the barrel to its FIG. 2 position. The bushing is very effectively and positively retained and guided for only the discussed pivotal movement relative to the slide and retaining rings 39, by virtue of the bearing engagement between spherical surface 38 of the bushing and the surfaces 29 and 42 of the slide and retaining ring. Surface 29 of the slide acts forwardly against the bushing, while surface 42 of the retaining ring acts rearwardly against the bushing, so that the latter is confined axially between these two surfaces, and is guided by those surfaces for only the discussed swinging movement.

During the recoiling motion of the slide to the FIG. 2 position, the fired round is ejected from the gun, and a next successive round is fed into the breech end of the barrel, following which the slide moves forwardly under the influence of recoil spring 19, to return itself and the barrel to the FIG. 1 firing or battery position. In this position, the forward end of the barrel is very effectively located by bushing 34, and the bushing is effectively located by the engaged spherical surfaces 29 and 42, so that there is no freedom for movement of any type of the forward end of the barrel, and the barrel is therefore positively located for accurate aiming and firing.

If bushing 34 or the barrel should become worn, or if for any other reason looseness should develop between the forward portion of the barrel and the slide, this looseness may be taken up by pressing plug 21 rearwardly far enough to enable the ring 39 to be turned about axis 27, and then turning ring 39 until this ring confines the bushing sufficiently tightly between surfaces 29 and 42, and constricts the bushing inwardly sufiiciently tightly against surface 37, to assure completely effective and accurate locating and guiding of the barrel.

We claim:

1. A gun including a receiver, a slide mounted for recoiling movement relative to said receiver, a barrel within said slide mounted for slight upward and downward swinging movement of the breech end of the barrel relative to said receiver during said recoiling movement of the slide, a bushing disposed about and locating said barrel and slidable therealong axially of the barrel upon said recoiling movement of the slide, a retaining structure .detachably connectible to said slide for locating the bushing axially relative thereto, means carried by said slide forming a surface engaging in a first axial direction against said bushing, said retaining structure having a second surface which at the time of attachment of said retaining structure is movable relative to said first mentioned surface and which engages in a second axial direction against said bushing in a relation confining the bushing axially between said surfaces, said surfaces and said bushing being shaped to guide the bushing for slight pivotal movement relative to the slide about an axis disposed essentially transversely of the barrel upon said slight swinging movement of the breech end of the barrel.

2. A gun as recited in claim 1, in which at least one of said surfaces is curved essentially spherically about a center located substantially on the axis of said barrel.

3. A gun as recited in claim 1, in which said bushing has an outer surface extending about said barrel and engaged by at least one of said surfaces of claim 1 and curved essentially spherically about a center located substantially on the axis of said barrel.

4. A gun as recited in claim 1, in which said two surfaces and an engaged outer surface of said bushing are all curved substantially spherically about a common center located substantially on the axis of said barrel.

5. A gun as recited in claim 1, in which said retaining structure includes a ring disposed essentially about said barrel and threadedly connectible into a forward end of said slide and threadedly adjustable relative to the slide to adjust said surfaces for proper confinement of the bushing.

6. A gun as recited in claim 1, in which said bushing is disposed about the barrel and is constrictable radially inwardly relative thereto to prevent looseness of the barrel in the bushing.

7. A gun as recited in claim 1, in which said bushing is disposed about the barrel and is constrictable radially inwardly relative thereto to prevent looseness of the barrel in the bushing, said surfaces and said bushing being shaped to cam the bushing radially inwardly in response to the exertion of axial forces against the bushing by said surfaces.

8. A gun as recited in claim 1, in which said retaining structure includes a ring disposed essentially about said barrel and threadedly connectible into a forward end of said slide and threadedly adjustable relative to the slide to adjust said surfaces for proper confinement of the bushing, said gun having a recoil spring, a plug urged forwardly by said spring, and interengaging means on said plug and said ring for releasably retaining the ring in any of different adjusted positions.

9. A gun as recited in claim 1, in which said retaining structure includes a ring disposed essentially about said barrel and threadedly connectible into a forward end of said slide and threadedly adjustable relative to the slide to adjust said surfaces for proper confinement of the bushing, there being means for releasably retaining said ring in any of different adjusted positions.

10. A gun as recited in claim 1, in which said two surfaces and an engaged outer surface of said bushing are all curved substantially spherically about a common center located substantially on the axis of said barrel, said bushing being disposed essentially annularly about said barrel but being interrupted at ont point about its periphery to enable constriction of the bushing against the barrel in response to the exertion of axial forces against the bushing by said surfaces, said gun having a recoil spring, a plug urged forwardly by said spring, said retaining structure being a ring disposed about the barrel and carrying said second surface to engage rearwardly against the bushing, said ring projecting into the slide and having external threads engaging internal threads in the slide to mount the ring for axial adjusting movement relative to the slide, said ring having an enlarged diameter flange forwardly of the slide, and detenting irregularities on said fiange and said plug interengageable to releasably retain the ring in any of different adjusted positions.

11. A gun as recited in claim 10, including a lug projecting from said plug, said slide having a portion containing said plug and having a recess receiving said plug in a relation retaining the plug against rotary motion.

12. A gun including a receiver, a slide mounted for recoiling movement relative to said receiver, a barrel within said slide mounted for slight upward and downward swinging movement of the breech end of the barrel relative to said receiver during said recoiling movement of the slide, a bushing disposed about and locating said barrel and slidable therealong axially of the barrel upon said recoiling movement of the slide, a retaining element disposed about said barrel and threadedly and detachably connectible to said slide and retaining and confining said bushing axially between said element and a shoulder carried by the slide and in a relation enabling slight pivotal but not axial movement of said bushing relative to the slde, and means for releasably retaining said element in any of various difierent rotatably adjusted positions relative to the slilde, and thereby retaining said element in different axially adjusted positions relative to said shoulder, to adjust the tightness of confinement of the bushing between said element and said soulder.

13. A gun including a receiver, a slide mounted for recoiling movement relative to said receiver, a barrel within said slide mounted for slight upward and downward swinging movement of the breech end of the barrel relative to said receiver during said recoiling movement of the slide, a bushing disposed about and locating said barrel and slidable therealong axially of the barrel upon said recoiling movement of the slide, a retaining element disposed about said barrel and threadedly and detachably connectible to said slide and retaining said bushing against removal from said slide and for slight pivotal movement relative to the slide, a recoil spring, a plug urged forwardly by said spring, and interengaging means on said plug and said element for releasably retaining the element in any of various different rotatably adujsted positions.

14. A gun as recited in claim 13, in which said interengaging means include a flange on said element, and detenting irregularities on said flange and said plug interengageable to releasably retain said element in any of said different adjusted positions.

References Cited UNITED STATES PATENTS 11/1949 Reilly 89163 11/1964 Charron 89196 

